K. Zioutas University of Patras / Greece + + O.K. Baker, A. Lindner, Y.K. Semertzidis, A. Upadhye Benefitted from: CERN, CAST + M. Betz, P. Brax, F. Caspers, J. Harris, M. Tsagri, J.-C. Vallet at al. / Tore Supra, L. Walckiers, … Vistas in Axion Physics: A Roadmap for Theoretical and Experimental Axion Physics through 2025 UW, Seattle / USA April 23-26, 2012 Equipment / people DE ↔ + Cross - disciplinary axion ↔ chameleon detection + ID DM > > novel concept … a by-product 1

CAST search for sub-eV mass solar axions with 3 He buffer gas. The CAST Collaboration, S. Aune et al, Phys. Rev. Lett.107 (2011) “Results from CAST … searches”, T. Papaevangelou, Moriond (March 2012): Prospects for Searching Axion-like Particle Dark Matter with Dipole, Toroidal and Wiggler Magnets O.K. Baker, M. Betz, F. Caspers, J. Jaeckel, A. Lindner, A. Ringwald, Y. Semertzidis, P. Sikivie, K. Zioutas, Phys. Rev. D85 (2012) Detection prospects for solar and terrestrial chameleons P. Brax, A. Lindner, K. Zioutas, Phys. Rev. D85 (2012) A chameleon helioscope O.K. Baker, A. Lindner, A. Upadhye, K. Zioutas, arXiv: v1arXiv: v1 Detection of radiation pressure from solar chameleons O.K. Baker, A. Lindner, Y.K. Semertzidis, A. Upadhye, K. Zioutas, arXiv: v1arXiv: v1 Related work … … and ref’s therein 2

3 => γ ↔ ALP oscillations?  Dark energy  m CHameleon = f(density)  Dark matter  m axion ~ μeV/c 2  HE  - transparency  m ALP < eV/c 2 / g aγγ ~ GeV -1 Chameleon instead? !  WD fast cooling  m axion ~10 meV/c 2  Solar corona heating  m axion ~17 meV/c 2 ~transparency  SN1987A  m axion ≤10 meV/c 2 “Open questions”  new physics?! Axion, Chameleons, WISPs to solve astrophysical puzzles

Telescopes: solar / relics + + Natural T. => work => direct signatures!  copy their workings RECYCLING  gain: time, $$, R&D, people (collaborators)  accelerating science cost efficiently, e.g., CAST >> >> Motivation – encouragement for: 4

CAST sensitivity per detector 0.3 counts/hour for g aγγ = GeV -1 and A = 14.5 cm 2 CAST  A superconducting LHC test-dipole tracks the Sun Sunrise /Sunset. Operation at T=1.8 K, I=13,000A, B=9T, L=9.26m, 4x 14.5 cm 2 A difficult experiment: the only moving 1.8K (!?) Expected signal X-Ray excess during 1-10 keV  E a  =4.2 keV Axion flux on earth + CAST : axion helioscope + … More see in 5

+ Recycled + cross-disciplinary + “firsts ” -  - LHC  Magnets, μWaves (cavities, antennas) -  - HEP det’s  MicroMEGAS -  - X-ray Astrophysics  Imaging / focusing X-Ray Telescope !! » + » S/B + a ID -  - Thermodynamics / CFD  to scan m a >0.1eV/c 2   [Results] CAST 6

7 » Signal / Noise + Signal + background With CCD at focal plane  rare! expected axion signal The recycled CAST XRTelescope CAST: Solar axion / chameleon ID

ℓ osc ≈ 3 4 keV / m axion ≈ 1 eV/c 2 → mm  m γ → m axion (Δρ/ρ < ) CAST: a difficult experiment  To be finalized soon! 8

CAST preliminary results for m a > 0.64 eV/c 2 10 trackings per density step, 0.4 eV (≈15.5 mbar)  improved sensitivity 2012 CAST 2012 … 2012 run 9

+ CAST: also ~axion haloscope + … … + ?) … CHameleon helioscope ( + haloscope ?) Relics CAST  Tore Supra / Tokamak  Need: MW antenna/cavities inside B  m a ≈ 0.1 – 100 μeV/c 2 …tbd Solar axions (CAST)  Need: « X-ray bckg. det’s + XRTs  best limit for m a <0.02 eV/c 2 Solar Chameleons CAST  Tore Supra  new !  Need: ~eV-keV threshold det’s  best sensitivity … tbd 10

11 ALPS / DESY CAST ADMX CDM axion search CDM axions / ALPs

Alternative magnets as haloscopes Dipole Wiggler Toroidal magnets L. Walckiers / CERN CAST DESY ATLAS  IAXO Tore Supra 1 st exploratory meeting on Tore Supra, CERN, 19/3/2012 >> experimental Challenge !! TE – modes couple to axions 12

Expected sensitivity OK Baker, et al., PRD85 (2012) Existing bounds for axionlike particles. The QCD-axion region is marked as the hatched band. In the orange region, axions are a natural candidate for DM. In the lighter shaded orange area, axions can still be DM, but with decreasing mass, this requires an increasing amount of fine tuning. Axion-like particles can be dark matter in a large part of the so-far untested parameter space. The right green (red) regions are the conservatively (realistically) expected sensitivity of a dipole or wiggler search for axion-like particle DM. The left green/red region shows the masses and couplings that could be probed in a setup with a toroidal magnet. … tbd 13

Box-in-the-box principle (3 GHz) ! Table-top particle physics ! See M. Betz, in PATRAS F. Caspers / CERN 14 E 2 -field suppression ~300dB ~ M. Betz, F. Caspers CERN

RF cavities inside toroidal magnets F. Caspers / CERN: “Either with single big cavities for low axion mass m a or with an array of smaller cavities for larger axion masses >> >> it’s delicate: each cavity has to be controlled individually, +in terms of its resonance frequency, independently” >>> tbd  >> >> Tore Supra JC Vallet Tore Supra = one of the largest Tokamaks  FREE NOW !! V = 30 m 3 & B = 4.5 T RF Heating Systems: MHz : 12 MW x 40s GHz : 8 MW cw GHz : 1 MW x 5s ITER ~2018 completion, start torus pump-down ITER ~10x 15

axions The magnetic field converts relic axions to MW photons, which excite the TE 011 mode. Photons Test signal A test signal is required in order to proof that for zero result the detector was working properly. This test signal is recommended to be used during the whole run; it should be near the res-frq but not at resonance. The inner walls might have to be covered by copper sheets, to achieve higher Q factors and better EMI shielding The microwave signal is coupled out by a small antenna and amplified. A commercial spectrum analyzer can be used to detect the axion signal. Tore Supra Tokamak, as relics haloscope M. Betz, F. Caspers / CERN 16

Preliminary simulation results Inner radius: 0.8m, outer radius: 2.4m TE 011 = H 011 mode, f = MHz  Most sensitive to axions with m a = 6∙10 -7 eV Wall materialConductivityUnloaded Q Stainless steel9.8e+5 S/m Copper5.8e+7 S/m Tore Supra as relics haloscope E–field of TE 011 mode (E CAV ) in TS cavity Static magnetic field of superconducting coils (B 0 ) 17

Expected sensitivity With the rather conservative parameters on the left (Q L =1000 & P det =5.5∙ W ), in 9h one could reach: g aγγ = 7∙ GeV -1 Tore Supra as relics haloscope M. Betz / CERN 18

[ADMX]: ~1m 3 (low frequency cavity), 7.6T; B 2 V ~ 50T 2 m 3  near quantum limit! Torre Supra: ~35m 3, 4T; B 2 V~500T 2 m 3  Low frequency ~150MHz  NEW ?  Without cavity mode? F. Caspers / CERN Higher axion rest mass, in a large volume (L coh ~10 – 100 m)  lose a factor of Q ~ 10 5 in production rate, but wideband! Y.K. Semertzidis / BNL  outcome ? Tore Supra as relics haloscope 19

Yannis Semertzidis, BNL19 March 2012 Tore Supra’… … relics sensitivity  first estimate ALPS / DESY CAST  ADMX 300K 3K 30mK 20

2004 Khoury, Weltman 2004 Chameleons … to explain DE … solar CHameleons ! 23

The analogue spectrum [h -1 keV -1 ] of regenerated photons as predicted to be seen by CAST: β m =10 6, B=30T in a shell of width 0.01R solar around the tachocline (~0.7R solar ). The effective mass of the chameleon inside the CAST pipe in vacuum is: m ch = 40 μeV/c 2 [keV] vacuum 0.1 mbar [keV] Converted Solar Chameleons: CAST, …, space Vacuum: ~ CH  γ ~ axion  γ ~ In CAST :  Low energy threshold: MM, CCD, …? ! + + vacuum CH conversion in vacuum with: BL=90Tm & β m =10 6 / β γ =  LE saturation! 24

 B X  virtual CHameleons CAST Enters only the coupling to photons ( β γ ) 25

XRT: Chameleon helioscope O.K. Baker, A. Lindner, A. Upadhye, K. Zioutas, arXiv: v1 [astro-ph.SR] arXiv: v1 enter β γ & β m Tore Supra CAST  double measurement!!  ~ x enhanced Φ CH !! E γ, CH > 50 – 100 eV X-Ray Telescope = Chameleon telescope E γ, CH < 10 – 50 eV ~any Telescope = Chameleon telescope 27

28..on a foil A new concept! arXiv: v1arXiv: v1 [astro-ph.IM] ? Equipment? … Finally, optomechanical experiments might be the mostly sensitive devices to react on an additional external radiation pressure component like that from solar chameleons. For example, the measured frequency drifts or the temporally observed irregularities in Figure 5.9 of [14] are of potential interest to be followed further; in particular, in case the observed behaviour resembles solar diurnal behaviour or other solar activity during the time period this measurement was performed. Therefore, such or other experiments being sensitive to external radiation pressure, when performed over longer time periods, i.e. at least one day, a correlation to solar activity should be searched for. Last but not least, the highest sensitivity of Gravitational Waves antennas might be of potential interest, provided their unprecedented sensitive performance is re-considered following the reasoning of this work about an ubiquitous dark radiation pressure.. Detection of radiation pressure from solar chameleons

Optical cavity … with a movable end mirror  ~pendulum. 31 P circ Mass m & Frequency ω Μ nm Membrane, ~50 ngram (r 1,t 1 ) Cavity length L ~7mm (r 2,t 2 ) ~2-3 mm

? some overlooked signal ? RT force threshold ≈ N ≈ 20nW Sensitivity ~ 20 nW/cm RT Jack Harris / Yale U. Φ solarCHam. <15 mW/cm 2  “Contigency” ~ nN=1W nanogram - nanometers

Resonant frequency drift B.M. Zwickl, Progress Toward Observation of Radiation Pressure Shot Noise, PhD-thesis, Yale University (2011) ( ). … of the membrane in 1 h run. origin?? “repeatedly” [Jack Harris/Yale U.] !!? Solar / celectial CHs !!? 33

H. Dole et al., A&A 451 (2006) 417 Cosmic CHameleons 36 O.K. Baker, K.Z. …the total probability to ALPs saturates to 1/3, which is the maximum (theoretical) attenuation.  Chameleons same spectrum with Φ CH ≤ 0.3Φ γ- CR IR Optical

Thanks Sun!! 37

31 Back-up slides

Lose a factor of Q~10 5 in production rate; overall lose a factor of 3x10 2 in S/N (for same total integration time). We gain a factor of 10 in B 2 V. Hence S/N loss ~30. If the receiver noise is 10 3 times higher (10 2 from temperature and 10 from frequency range)  Another S/N loss of ~30. Then the overall lost factor in S/N is The coupling is worse by Overall the expected sensitivity is ~ GeV ~10GHz axion mass range. Can we improve with B 2 V~500T 2 m 3 ? Tore Supra as relics haloscope Yannis Semertzidis, BNL19 March a

Opportunities on both sides, low + high frequency axions. see O.K. Baker, et al., PRD D85 (2012) Yannis Semertzidis, BNL Axion range coverage Central frequency [GHz] Quality factor Q Receiver noise T [K] Axion coupling [GeV -1 ] 5GHz/y x GHz/y x GHz/y x GHz/y GHz/y GHz/y March 2012 Tore Supra… 19b

13 Maximum energy at which a chameleon particle can be focused by an X-ray mirror with density 10 g/cm 3 (≈ the density of a Ni-coated X-ray telescope) and grazing angle ε, for several different chameleon models. The dotted horizontal and vertical lines illustrate one example of a 600 eV chameleon incident on a mirror of focusing angle 30', which is, for example, equal to the field-of-view of XMM/Newton. The chameleon will be focused by this mirror if n=4 and β m =10 6, but will pass through the mirror if n=1 and β m =10 4. K. Baker, A. Lindner, A. Upadhye, K. Zioutas, arXiv: v1 [astro-ph.SR] arXiv: v1

14 Minimum chameleon energy ω required for transmission through the atmosphere to the Earth’s surface. The atmosphere has at sea level a density of ρ m ≈ 1. 2 · 10 − 3 g/cm 3. (left) The minimum energy at normal incidence is the chameleon mass in the atmosphere, shown as a function of β m and n. (right) Chameleons at nonzero incident angles θ require greater energies for transmission, i.e., when the chameleons hit the plane of the denser surface less and less perpendicularly, more and more energetic chameleons can be reflected K. Baker, A. Lindner, A. Upadhye, K. Zioutas, arXiv: v1 [astro-ph.SR] arXiv: v1

Take for sure B ~0.1pTesla  BL ~ 10 9 Tm ~ 10 7 xCAST …the total probability saturates to 1/3  33% of the photons can convert into ALPs, which is the maximum (theoretical) attenuation.  Chameleons E.g.,A. Mirizzi, G. G. Raffelt, P. Serpico, Phys. Rev. D 76, (2007); M. A. SANCHEZ-CONDE et al., PHYSICAL REVIEW D 79, (2009) 34

although it is well established that the ultimate energy source is the coronal magnetic field, the question of how the magnetic energy is transformed to heat the coronal plasma is still to be solved.... one important issue is whether the heating is released gradually + continuously or in the form of discrete, rapid and intense pulses. April 2012